Make rook failsafe without scheduling key
(Alternatively force the usage of a scheduling key (mark it as mandatory))
The rook role fails if no scheduling key is defined:
TASK [rook_v1 : Create the operator] *****************************************************************************************************************************************************************************
fatal: [localhost]: FAILED! => {"msg": "The task includes an option with an undefined variable. The error was: 'rook_scheduling_key' is undefined...